Dry skin is often a problem in varying degree to most consumers. This condition is particularly evident in winter. In view of such a problem, personal care products like skin creams, lotions, toilet bars, shower gels and deodorants are normally formulated with at least one material suitable to address dry skin. These products can, to some degree, help in modulating symptoms such as itching, flaking and a displeasing dermal appearance.
Traditional classes of materials used to address dry skin and skin moisturization include occlusives like petrolatum and silicone oils, as well as keratolytic agents such as alpha-hydroxy acids. Other materials traditionally used to improve dry skin conditions are humectants. The substances generally classified as hydroxylated monomeric and polymeric organic substances are the most frequently used for this purpose. Glycerin, also known as glycerine or glycerol, is perhaps the most popular humectant employed in topical compositions.
New trends in skin moisturization have led to the use of quaternary ammonium compounds in topical skin formulations. Preferred quaternary ammonium compounds comprise a trimethyl ammonium group known generally via INCI nomenclature as a trimonium group. While such compounds are preferred for moisturization benefits, they tend to be unstable when, for example, water is present. This instability results in the generation of a nitrogen comprising group from the quaternary ammonium compound (i.e., a dealkylation and release of the characteristic trimonium group) which can produce an unpleasant odor, may diminish the moisturizing efficacy of the compound, or both. The generation of a nitrogen comprising group from the quaternary ammonium compound may also require more intense perfumes or fragrances in end use compositions. Moreover, such generation of a nitrogen comprising group in an end use composition typically requires product to be stored and shipped at cold temperatures so that product longevity may be prolonged.
There is an increasing interest to develop stabilized cationic ammonium compounds for all applications, and especially, applications where skin moisturization is desired. This invention, therefore, is directed to stabilized cationic ammonium compounds. The cationic ammonium compounds are stabilized with a metal chelator and, unexpectedly, the generation of a nitrogen comprising group in, for example, an aqueous environment is impeded. Such stabilized compounds are suitable for use in topical applications, including leave-on and wash-off compositions and even applications associated with oral care, laundry care and household care.